Refrigeration



June 29, 1943. R ANDERSON, J 2,323,186

REFRIGERATION Filed Aug. 26, 1941 2 Sheets-Sheet 1 M nrroR/vn' June 29, 1943. P. P. ANDERSON,,JR I 7 2,323,136

REFRIGERATION Filed Aug. 26, 1941 2 Sheets-Sheet 2 6, 49 P/5/ E -M '1 L L 0 37 55 1 :5

NVEN

%TTORNEY R Zak Patented June 29, 1943 UNITED STATES PATENT OFFICE REFRIGERATION Philip r. Anderson, Jr., Evansville, Ind, assignor to Serve], Inc., New York, N. Y.,'a corpora-- tion of Delaware Application august 26, 1941, Serial No. 408,318

8 Claims.

This inuention relates to refrigeration, and more particularly to refrigeration apparatus of the absorption type.

It is an object of the. invention to provide in apparatus of this type an improved liquid divider for subdividing liquid along a wall in such a manner that drops of liquid fall in rapid succession by gravity from spaced points at the bottom edge of the wall.

The above and other objects and advantages of the invention will be better understood from the following description and accompanying drawings donning a part of this specification, and

,of which 'view, taken at lines 4-4 of Figs. 3 and 5, to

illustrate more clearly parts of the liquid divider embodied in the absorber; and Y Fig.5 is a vertical view taken at line 5-5 of Fig. 4, partly broken away and in section, to illustrate more clearly th liquid divider embodying the invention.

Referring to Fig. 1, the present invention is embodied in two pressure absorption refrigeration apparatus like that described in application Serial No. 239,762 of A. R. Thomas and P. P.

Anderson, Jr., filed November 10, 1938, now Patent No. 2,282,503, granted May 12, 1942. A system of this type operates at low pressures and includes a generator or vapor expeller III, a. condenser ll, an evaporator l2 and an absorber H 'which are interconnected insuch a manner that the pressure differential in the system'is maintained by liquid columns.

The disclosure in the aforementioned Thomas and Anderson application may be considered as being incorporated in this application and, if desired, reference may be made thereto for a detailed description of the refrigeration apparatus. Briefly, the generator l includes an outer shell l within which are disposed a plurality of vertical riser tubes 16 having the lower ends thereof communicating with a space l1 and the upper ends thereof extending into and above the .bot-

and about the tubes l6 forms a steam chamber to which steam is supplied through a conduit 20 from a suitable sourceof supply.

The space I! provides for full length heating of riser'tubes IS with a vent provided at the upper end of shell l5 through which steam can flow into the atmosphere. Condensate formed in steam chamber l9 drains therefrom through a conduit 22 connected to the bottom part of shell l5. 1

The system operates at a partial vacuum and contains a water solution of refrigerant in absorption liquid, such as, for example, a water solution of lithium chloride or lithium bromide or a suitable mixture of su'chsalts'. Th heating of riser tubes l6 in generator ill by the steam causes refrigerant vapor to be expelled from ab-,

sorption liquid, the expelled vapor being effective to raise liquid absorbent by gas or vapor lift action. The expelled vapor passes'from the upper ends of the riser tubes is into the vessel 18, and thence flows through a conduit 23 into condenser II in which the expelled vapor is liquefied. The liquid refrigerant formed in condenser. flows through a 'U-tube 24, chamber 25 and conduit 28 into the upper part of evaporator II.

The refrigerant evaporates in evaporator l2 to, produce a refrigerating or cooling effect with consequent absorption of heat from the surroundings, as from a stream of-air flowing over th exterior surfaces of evaporator l2.

The refrigerant vapor formed in evaporator l2 flows therefrom to the absorber ll in which the vapor is absorbed into absorption liquid, as will be described more fully hereinafter. The absorption liquid enriched in refrigerant is conducted from absorber ll through conduit 21, a first passage in liquid heat exchanger 28, conduit 29, a vessel 30 and conduit 3| into space ll of generator I0. I Refrigeration vapor is expelled out of solution in generator ltlby heating,

and the solution is raised by gas or vapor lift action in riser tubes 16, as explainedv above.

The absorption liquid invessel I8 i deprived of refrigerant since refrigerant vapor has been I expelled therefrom in generator [0. The absorption liquid in vessel 18 flows therefrom through conduit 32, a second passage in liquid heat exchanger 28, and conduit 33 into the upper -part of absorber l4. This circulation of absorption liquid results from theraising of liquid in riser tubes I6, whereby the liquid can flow to. absorber l4 and return from the latter to generator ill by force of gravity. The upper part of vessel tom of a vessel Ill. The space' l9 within shell II 39 and vessel l9 are connected by a conduit 34,

' dium, such as water, forexample, which is conducted .from a suitable source of supply through a conduit to piping 36 which is vertically disposed within the absorber, whereby heat of absorption is given up to the cooling water. The cooling water flows from piping 36 through a I conduit 31 to condenser ll so that the same cooling water may be utilized to cool both condenser Hand absorber I4. The cooling water is discharged from condenser I i through a conduit 39.

I The. absorber I4 is generally like that described in'japplication Serial No. 350,234 of A. R. Thomas "and-P'.'"'P.' Anderson, -Jr., filed August 3, 1940.

Referring more particularly to Figs. 1, 2 and 3,

the absorber I4 includes a cylindrical shell 39 to which is secured the lower ends of evaporator headers, so .that vapor formed in evaporator 12- will pass through the headers into the shell 39. Within shell 39 is disposed the piping 36 formed to provide a plurality of vertical pipe banks arranged alongside of each other. Each pipe bank includes a plurality of substantially horizontal tubes 4i' located one above the other and connected'by bends 42. The ends of tubes 4| pass through andare secured at openings in end plates 43. The bottom corners of the end plates 43 are welded at 44 to the bottom parts I of shell 39, and the top corners thereof are secured by brackets 45 to the upper parts of the shellso that a rigid support is provided for the p p 36- a The ends of the bottom tubes 4| of each pipe bank are'connected to a manifold 46, as shown dividers comprising the troughs 56 from which liquid is distributed and siphoned onto the upper horizontal pipes of piping 36. The troughs 6 are formed by shallow trays 51 which are .U- shaped in section, as shown most clearly in Figs. 2 and 4. The trays 51 are located below the vessel. 56 with the ends thereof mounted on spaced tabs 43' formed at the top edges of end plates 43. The trays 51 aresecured to the tabs 43 in any suitable manner, as by welding, for example, so that the trays are rigidly supported in position.

The sidewalls of trays 51 are arranged toreceive inverted U-shaped cover plates 58 having relatively short arms 59 which extend downwardly into the troughs 56 and longer arms 66 most clearly in Figs. 1 and 2. The top tubes are similarly connected at one end to another horizontal manifold 41, as shown most clearly in Figs. 1 and 3. The conduits 35 and 31 through which cooling water enters and leaves piping 36 pass through end openings in. shell 39 and are connected to the manifolds 46 and 41, respectively. The cooling water entering through conduit 35 is distributed laterally in manifold 46 F with a. portion of the cooling water flowing upwardly through each vertical pipe bank. The several streams of cooling water flowing up wardly'through the pipe banks come together in the top manifold 4| and the cooling water then flows through conduit 3'l to condenser II, as explained'above;

The conduit 33 through which absorption liquid is introduced into absorber I4 terminates in a flattened or elliptical portion 48 disposedsubstantially at the center part of the shell 39. The elliptical portion 48 is closed at its extreme end and to an opening in'the bottom side thereof is secured a short tubular member 49 through which entering absorption liquid passes into a liquid receptacle 59. An annular member 5| is supported in a raised position in vessel 50 to prevent splashing of liquid entering the-latter;

The receptacle '56 is provided with spaced transverse walls 52 to provide smaller end compartments 53 into which liquid flows through V- shaped notches 54 inthe walls 52, as shown most clearly in-Fig. 2. From the smaller end com'partments 53 absorptron liquid passes through a plurality of pipes 55 into troughs 56 which are 10- extending downwardly at the outer sides of the troughs and terminating at regions below the" trays 51. The plates 58 are formedwith spaced.-

vertical slots 6i from the opposite ends ofwhich extend grooved or fluted portions 62 and 63,

the extreme bottom edges of the long arms which are notched at 64 with the grooved portions located between the inclined side edges of adjacent notches.

" The U-shapedcover plates 58 for the troughs 56 are preferably formed in a single stamping.

operation from flat sheet metal and then bent over a suitable rounded die to form the parallel arms 59 and 69. The plates 58'fit tightly .over

the sidewalls of trays 51 for the full length of the troughs 56. The grooves or fluted portions 62 are relatively shallow so that flow of liquid through the passages formed by these grooves, and the adjacent surfaces of the tray sidewalls is effected by capillary siphon action.

The distance that the short arms 59 of U-shaped plates 59 extend-into troughs 56 determines the height to which the liquid level must rise in the troughs before siphoning first starts by capillary action. In other words, go; a given height of the short arms 59, the liquid must rise to a definite level in troughs 56 for liquid in grooves 62 to rise.by capillary action in fixed pathsof flow at the inner surfaces of the tray sidewalls to the extreme top edges of the latter;

and, when the liquid level in the troughs reaches this definite level to effect such rise of liquid in grooves 62 to the'extreme top edges of the tray sidewalls, siphoning of liquid from within the troughs take place in fixed paths of flow formed by the grooves 62 at the inner'surfac'es of the tray sidewalls. Ai'tejr siphoning action has once been started, siphoning of liquid continues as long as the liquid-level in the troughs is at or .above the bottom edges of the short arms 59 of the U-shaped plates 58. If the siphon action is formed at the bottonrsides of the horizontal pipes broken, the liquid in troughs 56 must again rise to the definite level to cause capillary rise of liquid in the grooves 52 to the extreme top edges of the latter.

The liquid siphoned from troughs 56 flows down the surfaces of the outside arms 60 of U-shaped plates 58. By forming the shallow grooved portions 63 in alignment with the grooved portion 62 and notching the bottom edges of the long arms 60 to form teeth 65', the liquid at the outer surfaces of the tray sidewalls and surfaces of the long arms 50 is caused'to flow toward a number of spaced points at which drops of liquid are formed.

The drops of liquid formed at the teeth 65 fall therefrom in rapid succession onto the top surfaces of the uppermost horizontal pipe 4| of the piping 35. The teeth 65 serve as independent horizontal d'rip surfaces and are spaced as close- -ly together as possible, with the spacing being such that lateral bridg ng of the teeth with liquid is avoided. The drops of liquid falling by gravity from teeth 65 effect complete wetting of the exterior surfaces of the uppermost horizontal pipes 4|. The uppermost horizontal pipes 4| are directly beneaththe, arms 6|] of the U-shaped plates 58 and are preferably spaced from the bottom edges of the teeth 65 a vertical distance approximately the diameter of a drop of liquid.

To the bottom regions of all of the horizontal pipes 4|, except the lowermost horizontalpipe, are secured metal strips 66 havingU-shaped loops 61. The strips 66 are removably secured to the horizontal pipes 4| by spring clips 68, as shown in Figs. 4 and 5. The U-shap'ed loops 61 form M, a rainfall is simulated throughout the entire height of absorber M, the drops of liquid always falling onto the top surfaces of all of the pipes including those at the bottom part of the absorber. Any tendency for the liquid drops to run together to produce individual streams of liquid at localized areas is avoided, whereby the I entire exterior surfaces of the pipes 4| are com pletely wetted without reducing the capacity or I the ability of the absorber to absorb refrigerant vaporinto absorption liquid. The'slots 6| in the longer arms 60 of coverplates 58 are necessary when testing the liquid distributor in the presence of gas, such as air,

to prevent gas binding of the capillary passages. Such slots might not be necessary when the liquid divider is embodied in absorption refrigeration apparatus like that described providing inert gas were never present. However, the slots 8| might be necessary in the event absorption liquid enters the top part of absorber M at a tempera ture above its boiling point.

While a single embodiment of the invention has been shown and described, it will be apparent thatv modifications and changes may be made without departing from the spirit and scope of the invention, as pointed out in the following claims.

What is claimed is:

1. In an absorption refrigeration system having a generator, a condenser, an evaporator and an absorber, and members connecting the aforementioned parts for circulation of refrigerant and absorption liquid, structure to subdivide liquid including a liquid holder and a cover plate arranged to fit over a side wall of said holder,

' said plate being indented to provide relatively gether as possible with the spacing being such that lateral bridging of the loops.with liquid is avoided. Also, the loops 6! are preferably spaced from the top surfaces of the horizontal pipes 4|.

directly beneath the loop a vertical distance approximately the diameter of a drop of liquid.

While flowing over the exterior surfaces of sorbs refrigerant vapor passing into the shell 39 from evaporator l2 through the headers 40. The

heat of absorption resulting from absorption of refrigerant vapor by the absorption liquid is given up to the cooling water which flows inside the pipe Al. The absorption liquid .flowsout from the bottom of shell 39 to generator I0 in a path of flow including conduit 21, as explained above.

In the type of absorber just described, it is exceedingly important that distinct drops of liquid fall in rapid succession from the sidewalls of the troughs 56 onto the horizontal pipes 4|. This is readily accomplished at the-troughs 56 by providing the one-piece U-shaped cover-plates 58, whereby liquid is siphoned from the trays 51 onto the upper horizontal pipes 4| with the drops of liquid falling from the teeth simulating a rainfall. The- U-shaped coverplates 58 may be formed in a single stamping operation and then small passages for siphoning liquid upwardly in fixed paths of flow by capillary action from within said holder over said side wall.

2. In an absorption-refrigeration system having a generator, a condenser, an evaporator and an absorber, and members connecting the aforementioned parts for circulation of refrigerant and absorption liquid, structure to subdivide liquid including a liquid holder,- a U-shaped cover plate having substantially parallel arms arranged to fit over a side wall of said holder, said arms being indented and adapted to overlie theinne'r and outer surfaces ofsaid wall, said arm overlying the outer surface of said wall depending below the bottom of said holder and being notched to provide spaced teeth, and said cover plate being so constructed and arranged that said indentations therein form capillary passages through which liquidtis siphoned upwardly in fixed paths of flow from within said holder by capillary siphon action,.said spaced teeth serving as independent drip surfaces from which drops of siphoned liquid fall by gravity.-

3. In an absorption refrigeration system having a .generator, a condenser, an evaporator and an absorber including piping having a substantially horizontal pipe section, structure to subdivide liquid to produce and maintain a liquid film on said pipe section comprising a substantially horizontal liquid holder, and a cover plate for a side wall ofsaid holder having one arm extending within said holder and another arm overlying the outer surface of said wall and depending belowthe bottom of said holder, 'said other arm having the bottom edge thereof formed to provide spaced independent drip slirfaces, and said cover plate being indented and arranged to provide relatively small passages for siphoning liquid-upwardly in fixed paths of fiow from within said holder onto 'said other arm by capillary siphon action so that drops of siphoned liquid fall in rapid succession from said drip surfaces by gravity.

4. In an absorption refrigeration system having a generator, a condenser, an evaporator and an absorber, and members connecting the aforementioned parts for circulation of refrigerant and absorption liquid, structure to subdivide liquid including a substantially horizontal liquid holder and a cover plate arranged to fit snugly over a wall of said holder, said cover plate being formed from a single sheet of metal having ashort arm extending into said holder and a longer arm overlying the outside of said wall and extending below the bottom of said holder, the bottom edge of said longer arm being notched to provide spaced teeth, said longer arm being slotted at spaced intervals with grooved or fluted portions extending upwardly and downwardly from said slots, the grooved portions extending downwardly from said slots in said longer arm terminating in the region of said drip surfaces, and said grooved or fluted portions extending upwardly from said slots terminating at the bottom edge of said short arm to provide relatively narrow passages for siphoning liquid upwardly in fixed paths of flow from within said holder by capillary siphon action, said spaced teeth serving as independent drip surfaces from which drops of siphoned liquid fall by gravity.

5. In an absorption refrigeration system having a generator, a condenser, an evaporator and an absorber including piping having a substantially horizontal pipe section, and members connecting the aforementioned parts for circulation of refrigerant and absorption liquid, structure to subdivide .liquid including a substantially horizontal liquid holder disposed above said pipe section, and an indented cover plate having parallel arms arranged to fit over a side wall of said holder with one arm extending into said holder and another longer arm overlying the outside of said wall and depending below the bottom of said holder, the bottom edge of said longer arm being formed to provide horizontal drip surfaces spaced from said pipe section; and

said cover plate being formed and arranged to provide relatively narrow passages for raising liquid upwardly in fixed paths of flow from within said holder onto said longer arm by capillary siphon action to cause drops of liquid to fall in rapid succession from said drip surfaces onto said pipe section to maintain the exterior of the latter in a completely wetted state.

6. In an absorption refrigeration system having a generator, a condenser, an evaporator and an absorber including piping having a substantially horizontal pipe section, and members connecting the aforementioned parts for circulation of refrigerant and absorption liquid, structure to subdivide liquid including a substantially horizontal liquid holder having a smooth side wall and a one-piece U-shaped cover plate arranged to fit snugly over said side wall, said 7 cover plate being indented and arranged to provide relatively narrow passages for siphoning liquid upwardly in fixed paths of flow from within said holder by capillary siphon action, the portion of said cover plate overlying the outside of said side wall being formed to provide spaced independent drip surfaces from which drops of liquid can fall in rapid succession by gravity.

'7. A liquid divider of the character described comprising a substantially horizontal liquid holder having a smooth side wall and a onepiece cover plate arranged to fit snugly over said side Wall and being indented to provide relatively narrow passages to cause liquid to flow upwardly in fixed paths of flow from within said holder by capillary siphon action, the portion of said cover plate outside said holder being formed to provide a plurality of independent horizontal drip surfaces from which drops of siphoned liquid can fall in rapid succession by gravity.

8. In absorption refrigeration apparatus, a liquid divider comprising a wall at one side of which a body of liquid is adapted to be maintained, and a one-piece cover plate having an arm at each side of said wall, and said arms being formed with vertically extending grooves to form passages for raising liquid upwardly at one side of said wall in fixed paths of flow by capillary siphon action onto the other side of said wall for downfiow at the other side.

PHILIP P. ANDERSON, JR. 

